dumping bbc micro discs

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ELITE
Posts: 8
Joined: Wed Apr 25, 2012 11:54 pm

dumping bbc micro discs

Post by ELITE »

Hi,

I am uising a teac 55 drive.

All the games load without any problems when using this drive.

All the discs have a single index hole and when formatting or verifing side 1 on a bbc an error message is returned.

Can it be assumed that these discs are therefore single sided?

Also some discs are dual formatted ie 40/80 track.

If an image is written back to disc using a sony 920 drive which automatically detects no of tracks then won't this cause a problem with loading from this drive a dual formatted disc?

Btw some discs are 80 track only and some are 40 track only.

In light of the above information should i set the teac drive to 80 track mode when making images for preservation irrespective of the format of the disc ?

What is the command line to make an image of bbc discs for submission?

for some with 2 index holes and data on both sides should i just flip the disc and copy using the command i asked for before?

Should I give info to sps about which side each dump is of ie side 0 or 1?

Thanks Elite

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IFW
Posts: 3079
Joined: Mon Nov 08, 2010 2:42 pm

Re: dumping bbc micro discs

Post by IFW »

Short answer:
Please use -i2 to have preservation parameters set and then use the correct format as a guide format.
-i2 would ensure to have all tracks dumped, regardless of disk format.

Ideally, all games made for flippy disk systems should be dumped with a modified flippy drive.
Do you have access to such a drive?

ELITE
Posts: 8
Joined: Wed Apr 25, 2012 11:54 pm

Re: dumping bbc micro discs

Post by ELITE »

so i'll use the command:
DTC -d0 -fbbcgamename -i0 -i2 -i5

where 1st parameter is drive, 2nd is stream file and third is no of reads.

Can you confirm this?
what do you mean by " ...then use the correct format as a guide format"?


Also I don't have a flippy drive so can anyone help?

How can you tell which side is side 0 of a flippy disc and if using a modified drive does it matter which side is which?

Thanks
elite

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IFW
Posts: 3079
Joined: Mon Nov 08, 2010 2:42 pm

Re: dumping bbc micro discs

Post by IFW »

guide format is what you set as -i5
-i0 and -i2 are special formats needed for creating the stream files correctly.
-i5 would be the format the image would be verified against during dumping for errors - in this case that's AmigaDOS which is probably not what you want for BBC :)
-i4 or -i3 should work, depending on the disk content.

It does matter which side is which for historical accuracy.
The order that should be kept with a flippy drive is what you use when you insert a disk into drive normally, the plain (usually labelled) surface up.

ELITE
Posts: 8
Joined: Wed Apr 25, 2012 11:54 pm

Re: dumping bbc micro discs

Post by ELITE »

Hi again

"-i4 or -i3 should work, depending on the disk content". Does this mean I should dump ie create stream files using bot i4 & i3 since I don't know if which of the discs use fm or mfm, if any? Or is there a way to check this before creating stream files for each disc?

So I can start dumping can you tell me the command line to be used?

Thanks
Elite

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mr.vince
Posts: 2135
Joined: Tue Oct 05, 2010 5:48 pm

Re: dumping bbc micro discs

Post by mr.vince »

Please try -i0 -i2 -i3
if you get only errors, try -i0 -i2 -i4

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IFW
Posts: 3079
Joined: Mon Nov 08, 2010 2:42 pm

Re: dumping bbc micro discs

Post by IFW »

If most/all of the tracks show up as unformatted, then try -i4

BBCMicroUser
Posts: 33
Joined: Sun Feb 19, 2012 4:41 pm

Re: dumping bbc micro discs

Post by BBCMicroUser »

Here's what I use to dump non-protected BBC disks as sector images.....

Code: Select all

DFS disks (side 1) 40 track

dtc -d0 -fbbcgamename.ssd -s0 -e79 -g0 -z1 -k2 -n -16 -i3

DFS disks (side 2) 40 track

dtc -d0 -fbbcgamename.ssd -s0 -e79 -g1 -z1 -k2 -n -16 -i3

DFS disks (both sides) 40 track

dtc -d0 -fbbcgamename.dsd -s0 -e79 -z1 -k2 -n -16 -i3



DFS disks (side 1) 80 track

dtc -d0 -fbbcgamename.ssd -s0 -e79 -g0 -z1 -k1 -n -16 -i3

DFS disks (side 2) 80 track

dtc -d0 -fbbcgamename.ssd -s0 -e79 -g1 -z1 -k1 -n -16 -i3

DFS disks (both sides) 80 track

dtc -d0 -fbbcgamename.dsd -s0 -e79 -z1 -k1 -n -16 -i3



ADFS disks (side 1) 40 track

dtc -d0 -fbbcgamename.adf -s0 -e79 -g0 -z1 -k2 -n -16 -i4

ADFS disks (side 1) 80 track

dtc -d0 -fbbcgamename.adf -s0 -e79 -g0 -z1 -k1 -n -16 -i4

ADFS disks (both sides) 80 track

dtc -d0 -fbbcgamename.adl -s0 -e79 -z1 -k1 -n -16 -i4
For STREAM dumps add -i0 -i2 to the command line.

Hope this helps,

BBCMicroUser

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IFW
Posts: 3079
Joined: Mon Nov 08, 2010 2:42 pm

Re: dumping bbc micro discs

Post by IFW »

Also, if you do this for preservation of commercial disks do not specify the track boundaries, ie -s -e parameters.
Many commercial disks contain information from track 80, if nothing else, duplicator info.

ELITE
Posts: 8
Joined: Wed Apr 25, 2012 11:54 pm

Re: dumping bbc micro discs

Post by ELITE »

Hi

It just occurred to me that if we are specifying the format eg fm, mfm etc before dumping begins(for preservation only) then it should not matter what format the disc is in as the device measures flux transitions etc ie analysing and measuring the various parameters on the disc surface. Therefore by specifyng the disc type it is possible that (in my case a bbc disc) a disc maybe protected by a method which is not recognised by selecting the specific eg protection methods from different machine systems used on 1 computer.

If you selected 'make stream file' without having to select disc protection type (because were analysing disc on lowest level) that would make sense to me nad the ipf file should contain the info to write back the ipf to disc again without stating parameters.

So in short, by making assumptions of disc type we are possibly not including all protection parameters leaving the possibility that not all 'data'(flux info) from disc has been copied as it should.

You guys are the experts so obviously you have thought aboy this so a simple none technical explanation would be sufficient as to why your methods do work with 100% accuracy.

Another reason it ocurred to me was being told to use -i3 and if too many errors then -i4. You use the term 'most or all of disc gives errors then use i4'. What if the disc gives 40% or 50% errors on one setting eg -i3 then can you say with 100% certainty that -i4 will work?
Or does i3 give lower file size & is quicker so if possible use i3 & if time is not an issue & to be sure that all my commercial bbc discs are fully 'copied' should I use -i4?
Also how sure are you that once a stream file is sent to you & you make an ipf, that I can essentially throw my original disc out & if there are any write issues as people have had in the past, it has nothing to do with the ipf image & at worst its the way the dtc software is written and can be improved upon at a later date(at this point i'd be worried that i havn't got the original disc or is damaged and the ipf is no good).
I hope you guys can see where I am coming from & comfort me with your explanations. :lol:

Thanks
Elite
Ps my object is to have only ipf files of all my commercial programs which are protected. What % of disc is unformatted for each game I do not know.

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